脑铁含量和T2弛豫时间的关系

探讨脑铁含量与T2弛豫时间的关系。材料与方法选择15例意外死亡尸体脑，除外脑外伤、脑梗塞、脑肿 瘤、神经和精神系统疾病，测量双侧苍白球、尾状核、丘脑、黑质、红核、齿状核及双侧额、枕、颞叶白质T2弛豫时间(SE序 列T1WITR/TE500/40ms；T2WITR/TE2700/80ms)和铁含量，对脑铁含量与T2弛豫时间行相关性分析。结果灰质核团 T2弛豫时间随脑铁含量增加而缩短，脑白质T2弛豫时间无变化趋势。灰质核团(除苍白球)r值在-0.6928～-0.9440之 间，苍白球和白质区r值在-0.0418～-0.3722之间。结论(1)苍白球区T2弛豫时间易偏移不宜作为脑铁MRI研究区 域；(2)脑灰质核团的T2弛豫时间下降主要与铁沉积有关，脑白质T2弛豫时间与多种因素有关。

Correlation Between Brain Iron and T2 Relaxation Time

Purpose: To study correlation between brain iron content and T2 relaxation time. Materials and methods: We select 15 cadaver brain died of accident, excluding brain trauma, hemorrage, infaractin, tumor, neuropathic and psychiatric diseases. T2 relaxation time value (spin echo pluse sequence: T1WI TR/IE500/40m, T2WI TR/TE2700/80ms) and iron contents of globus pallidum, caudate, thalamus, substantia nigra, red nucleus, dentate nucleus and white matter of frontal, occipital and temporal lobes were measured, the relations of thegm were analyzed. Results: T2 relaxation time of gray matter nucleus was shorten because of iron content increasing, and that of white matter had not this change. The value of gray matter nucleus (excluding globus) was from - 0.6928 to -0.9440 (p< 0.05), which of globus pallidums and white matter was from- 0. 0418 to - 0.3722 (p > 0.05). Conclusion: (1)T2 relaxation time of globus pallidums is not suitable for us to study brain iron with MRI because it is easy to change (2) The shortening of T2 relaxation time of gray matter nucleus is relative to the iron deposit, and that of white matter is relative to many other factors.